This is one of my favorite iPhoto bugs. It's a meaningless error message that seems to arise from several problems.

The two most common causes are corruption in a thumbnail and a less common problem related to disk size. One time it occurred to me every time an export reduced free disk space to exactly 3GB. DECREASING free disk space beyond that level allowed export to occur.

Known fixes:

1. Deleting the prefs as mentioned here.
2. Upgrade to 4.01 (didn't work for this guy).
3. Deleting the image thumbnail caches (as per the referenced kb article).
4. Splitting exports in half until one isolates the "bad" image, then performing an operation that regenerates the thumbnail. (Crop then revert.)

In general a lot of OS X problems seem to be related to cache corruption. Makes me wonder about the low level BSD interfaces.

iPhoto has had a rocky development course. Rumor has it the product team has undergone a shakeup, but rumor also has it that iPhoto gets very little respect and focus within Apple. Rumor is worth what you pay for it :-).

I guess Jobs was always a guitar geek and not a camera nerd.

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John Faughnan
jfaughnan@spamcop.net
www.faughnan.com

The problem just hit me again. This time I tried Panther Cache Cleaner and deleted all the caches (deep clean). I didn't remove the plist file. The problem resolved. Deleting the thumb images didn't help.

I wonder how bad Panther's underlying cache corruption problems are.

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John Faughnan
jfaughnan@spamcop.net
www.faughnan.com